title: Nickel-aluminum layered double hydroxide as a nanosorbent for selective solid-phase extraction and spectrofluorometric determination of salicylic acid in pharmaceutical and biological samples.
abstract: The nickel-aluminum layered double hydroxide (Ni-Al LDH) was synthesized by a simple co-precipitation method and used as a solid-phase extraction (SPE) sorbent for separation and pre-concentration of trace levels of salicylic acid (SA) from aqueous solutions. Extraction of analyte is based on the adsorption of salicylate ions on the Ni-Al (NO(3)(-)) LDH and/or their exchanging with LDH interlayer NO(3)(-) ions. The retained analyte on the LDH was stripped by 3 mol L(-1) NaOH solution and its concentration was subsequently determined spectrofluorometrically at λ(em)=400 nm with excitation at λ(ex)=270 nm. Various parameters affecting the extraction efficiency of SA on the Ni-Al (NO(3)(-)) LDH, such as pH, amount of nano-sorbent, sample loading flow rate, elution conditions, sample volume and matrix effects were investigated. In the optimum experimental conditions, the limit of detection (3s) and enrichment factor were 0.12 μg L(-1) and 40, respectively. The relative standard deviation (RSD) for six replicate determinations of 10 μg L(-1) SA was 2.3%. The calibration graph using the pre-concentration system was linear in the range of 0.3-45 μg L(-1) with a correlation coefficient of 0.9985. The optimized method was successfully applied to the determination of SA in blood serum, willow leaf and aspirin tablet.
authors.affiliation: Department of Chemistry, Faculty of Sciences, Azarbaijan University of Tarbiat Moallem, 35 Km Tabriz-Marageh Road, P.O. Box 53714-161, Tabriz, Iran. h.abdol@azaruniv.edu
authors.forename: H
authors.initials: H
authors.lastname: Abdolmohammad-Zadeh
authors.forename: S
authors.initials: S
authors.lastname: Kohansal
authors.forename: G H
authors.initials: GH
authors.lastname: Sadeghi
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry*; D002138:Calibration; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D009532:Nickel / Q000737:chemistry*; D004364:Pharmaceutical Preparations / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry*; D012015:Reference Standards; D015203:Reproducibility of Results; D020156:Salicylic Acid / Q000032:analysis*; D032108:Salix / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D004364:Pharmaceutical Preparations; D000536:Aluminum Hydroxide; D009532:Nickel; D020156:Salicylic Acid